Abstract: A system and method for determining a coagulation time, e.g., TT, PT, aPTT, and ACT, of a test sample deposited in a test cartridge is disclosed. A cartridge housing having upper and lower major sides and a minor sidewall encloses a test chamber having a test chamber pivot element and is provided with a cartridge port for introducing a test sample into the test chamber,. Ferromagnetic agitator vane leaflets extend from an agitator pivot element supported by the test chamber pivot element intermediate the upper and lower major sides for rotational motion. The agitator vane leaflets can be swept, in response to an external magnetic field, through the test sample in the absence of coagulation. A timer is started when the agitator movement is commenced whereupon the agitator moves freely. Resistance to agitator movement due to coagulation is detected, and the coagulation time is measured.

Abstract: Improved methods and apparatus that make more accurate and reduces risk of filling reaction chambers of cartridge cells with blood samples to conduct blood coagulation tests of the type employing the plunger technique are disclosed. A cartridge holder is provided that secures a test cartridge in a fixed upright position and deflects the plunger flag of each cartridge cell to enable manual insertion of a blood dispenser deeply into the reaction chamber to fill the reaction chamber and avoid contamination of surfaces of the cartridge outside the reaction chamber. Preferably, the cartridge holder provides illumination of the reaction chamber during filling, so that the user can judge when the reaction chamber is properly filled with blood dispensed from the blood dispenser. The cartridge holder may incorporate image magnification to facilitate viewing of the reaction chamber as it is filled.

Abstract: Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer.

Abstract: A system and method for determining a coagulation time, e.g., thrombin time, PT, aPTT, and ACT, of a blood sample deposited in a test cartridge is disclosed. The test cartridge comprises a blood receptacle that is open to the atmosphere into which a blood sample is to be deposited, a vacuum port that is open to atmosphere, and a spiral capillary within the test cartridge having a capillary length and cross-section area, a first capillary end of the spiral capillary open to the blood receptacle and a second capillary end of the spiral capillary open to the vacuum port, whereby the spiral capillary is closed to atmosphere. When a blood sample is deposited in the blood receptacle, a vacuum is drawn through the vacuum port and the blood is drawn through the spiral capillary until coagulation occurs. A pressure change is detected, and the coagulation time is measured.

Abstract: A system and method for determining a coagulation time, e.g., TT, PT, aPTT, and ACT, of a test sample deposited in a test cartridge is disclosed. A cartridge housing having upper and lower major sides and a minor sidewall encloses a test chamber having a test chamber pivot element and is provided with a cartridge port for introducing a test sample into the test chamber,. Ferromagnetic agitator vane leaflets extend from an agitator pivot element supported by the test chamber pivot element intermediate the upper and lower major sides for rotational motion. The agitator vane leaflets can be swept, in response to an external magnetic field, through the test sample in the absence of coagulation. A timer is started when the agitator movement is commenced whereupon the agitator moves freely. Resistance to agitator movement due to coagulation is detected, and the coagulation time is measured.